I also wanted to add that this actually happens a lot when children are around the age your children are. I have noticed this here at PC but also noticed it happening with many couples that were parents of my daughter's piers when they were this age too.

I have a feeling that some of this is a midlife crisis issue, but also due to the age when children are getting ready to leave the nest and how that can leave a parent feeling like they have lost their identity. Something is missing and often that can be the core of a partner's problem. This isn't something you caused or something you failed at either. Your wife genuinely feels something is missing in herself and often this feeling experienced isn't easy to explain. What filled your wifes life and changing and she is starting to experience the void that creates. Many parents experience this challenge and they even have a name for it called "empty nest syndrome".

Given that you have been the active bread winner part of your life is still there for you as you are years yet away from retirement. For her it's different because due to her being the one who's life really revolved around being a homemaker, that is changing and leaving a lot of void, a void you alone cannot fill in your wife.

However, that being said, due to Covid and how that has affected our economy and ability to actually go off to college, many your children's age will actually be staying and living at home longer. I recently met a woman that had her last child graduating and getting ready to leave and they sold their big house and downsized before Covid hit. Now with this Covid challenge her children are living at home again and she now lacks the room she had once had. So now their new smaller home is tight lacking space for the family to all be living there again.